"I can understand people are very hungry for details but because of the nature of this investigation, and the fact that it is ongoing, I'm just not in a position to confirm anything," Justice Minister Michael Keenan said.

Standard items such as smart phones, an iPad, SIM cards and cars were seized at raided properties over the weekend.

At Lakemba, documentation for a Jakarta-to-Sydney flight route was found in the garbage.

Khaled Khayat, one of four men under investigation. Source: 7 News

Police also seized a note linked to the home raided in Surry Hills, where components of a meat grinder and "multi-mincer" were found.

Investigators are examining whether a mincer was to be potentially used as a bomb designed to disperse poisonous gas mid-flight.